Monday, March 1, 2010

Stephanie's Reflection

Limacon
r = a+b sin theta
r = a+b cos theta

Cardioid
a-b sin theta
a-b cos theta

Rose
r = a sin n theta
r = a cos n theta
n is how many petals

Archimedes Spiral
r = a theta +b

Logarithmic Spiral
r=a^theta b

Converting
polar to rectangular
x=r cos theta
y=r sin theta

rectangular to polar
r=+/- sqrt x^2 + y^2
theta is (x/y)

Trig Chart:


sin0=0
cos0=1
tan0=undefined
sec0=1
cot0=0

30°
sinπ/6=1/2
cosπ/6=√3/2
tanπ/6=√3/3
cscπ/6=2
secπ/6=2 √3/3
cotπ/6=√3

45°
sinπ/4=√2/2
cosπ/4=√2/2
tanπ/4=1
cscπ/4=√2
secπ/4=√2
cotπ/4=1

60°
sinπ/3=√3/2
cosπ/3=1/2
tanπ/3=√3
cscπ/3=2 √3/3
secπ/3=2
cotπ/3=√3/2

90°
sinπ/2=1
cosπ/2=0
tanπ/2=undefined
cscπ/2=1
secπ/2=undefined
cotπ/2=0

1 comment:

  1. For example:

    x² + 6x - 2 = 0

    * anytime you are solving a quadratic you’re finding x-intercepts


    Move the constant term to the right side:
    x² + 6x = 2

    Take half of the coefficient on the x-term (divide it by two, and keeping the sign), and then square it. Add the squared value to both sides of the equation:

    x² + 6x + 9 = -2 + 9

    Convert the left-hand side to squared form. Simplify the right-hand side:

    (x + 3)² = 7


    * the # half of the coefficient goes in the parentheses.


    Square-root both sides:

    x + 3 = √7


    Solve for "x =". Remember to put the "±" on the right side and that it gives you two solutions.

    x = -3 ± √7

    The two points for this solution are:

    (-3 + √7) , (-3 -√7)

    ReplyDelete